Caterpillar Inc.

Douglas A Carlson

Todd D Creger

Javad Hosseini

Sairam Gopalan Velamakanni

Aaron Y Ho

Warren Pepper

Catrina Swan

Scott Alan Leman

Stephen C Garnett

Michael D Betz

Michael D Anderson

Alan L Stahl

Randall M Mitchell

David L Dickrell

Kenneth P Liesener

Sri K Rangarajan

Jeffery L Scott

Wayne M Ferrell

Danish A Hussain

A machine powertrain includes an engine operably connected to a torque converter and a transmission. A switch associated with the torque converter provides a locking signal indicative of a locked or unlocked condition of the torque converter. A throttle sensor associated with the throttle provides a throttle signal. An electronic controller receives the locking signal and the throttle signal, and controls operation of the engine at least partially based on the throttle signal and the locking signal. The electronic controller determines whether a locked or unlocked condition of the torque converter is present based on the locking signal, determines whether a part throttle operating condition or a full throttle operating condition is present based on the throttle signal, and selects a load-control power curve when the part throttle operating condition is present and when the torque converter switches from the unlocked to the locked condition.

Machine powertrain and method

A machine powertrain includes an engine operably connected to a torque converter and a transmission. A switch associated with the torque converter provides a locking signal indicative of a locked or unlocked condition of the torque converter. A throttle sensor associated with the throttle provides a throttle signal. An electronic controller receives the locking signal and the throttle signal, and controls operation of the engine at least partially based on the throttle signal and the locking signal. The electronic controller determines whether a locked or unlocked condition of the torque converter is present based on the locking signal, determines whether a part throttle operating condition or a full throttle operating condition is present based on the throttle signal, and selects a derated power curve when the part throttle operating condition is present and when the torque converter switches from the unlocked to the locked condition.

A method of maintaining a constant ground speed of a work machine having an engine, powertrain, and at least one electronic control module (ECM) is disclosed. The method included sensing a parameter indicative of the ground speed of the work machine and responsively producing a signal indicative of the actual ground speed, providing a predetermined maximum ground speed of the work machine, receiving the signal indicative of the actual ground speed and the predetermined maximum ground speed of the work machine by the ECM, applying an algorithm to determine the desirable RPM of the engine of the work machine, and modulating the engine RPMs to the desirable engine RPMs to maintain a constant ground speed of the work machine.

Method for controlling the ground speed of a work machine

A method and apparatus for determining a value of torque at a desired location on a machine. The method and apparatus includes choosing the desired location, determining an operating condition relevant to the desired location, determining a plurality of parameters of the machine, and determining a value of torque at the desired location as a function of the operating condition and the plurality of parameters.

Method and apparatus for determining torque at desired locations on a machine

An enhanced braking mode for a work machine includes activating engine compression release brakes while placing a torque converter in an overspeed condition. By doing so, both the engine and the torque converter contribute to decelerating the work machine. This combined braking horsepower is greater than that available using the engine compression release brakes with the torque converter in a locked condition. In addition, the braking horsepower available in this enhanced braking mode is comparable to that available with the employment of hydraulic retarders, which can be substantially more expensive, and require additional hydraulic cooling system capability. The enhanced braking mode is preferably carried out automatically by the electronic control module when the vehicle is in a retarding mode.

Work machine having a drive train with an enhanced braking mode

A control apparatus for a transmission having a first gear ratio, a second gear ratio, and an output shaft is disclosed. The apparatus includes an actuator assembly which disengages the first gear ratio from the output shaft and engages the second gear ratio to the output shaft in response to an upshift signal. The apparatus further includes a memory device which stores a conservative upshift point and an aggressive upshift point. The apparatus yet further includes a controller operable to read the aggressive shift point and the conservative shift point from the memory device. The controller is further operable to determine if the transmission is operating in a conservative mode of operation or operating in an aggressive mode of operation. The controller is yet further operable to generate the upshift signal at the aggressive upshift point if the transmission is operating in the aggressive mode of operation or generate the upshift signal at the conservative upshift point if the transmission is operating in the conservative mode of operation. A method of controlling a transmission assembly is also disclosed.

Method and apparatus for adaptively shifting a powershift transmission

A drive line assembly for a work machine is disclosed. The drive line assembly includes an engine driving an engine output shaft and an engine speed sensor which generates engine speed signals indicative of a speed of the engine output shaft. The drive line assembly further includes a torque converter driven by the output shaft which drives a transmission input shaft and a transmission speed sensor which generates transmission speed signals indicative of a speed of the transmission input shaft. The drive line assembly yet further includes a transmission driven by the transmission input shaft and having a first speed clutch, a second speed clutch, and a directional clutch, and a controller. The controller is operable to determine a torque converter ratio from the engine speed signal and the transmission speed signal and determine an engine load based on the torque converter ratio. The controller is further operable to control engagement of the first speed clutch, the second speed clutch and the directional clutch based on the engine load. A method controlling a drive line assembly is also disclosed.

Method and apparatus

A control system and method is provided for changing the shiftpoints of a transmission for part throttle shifting. A input section delivers a actual gear signal, a engine speed signal and a torque converter output speed signal A controller receives the input signals and varies the transmission shiftpoints relative to the received signals. The controller also delivers signals to the transmission to upshift, downshift or that no shift is necessary.

Control system for an automatic transmission having shift points based

In one aspect of the present invention, a method of effecting shifts in a vehicle is disclosed. The method modifies the transmission shiftpoints in response to the number of upshift successes and failures.

Method for modifying the shiftpoints of an automatic transmission

In one aspect of the present invention, a method of effecting shifts in a vehicle is disclosed. The method modifies the transmission shiftpoints in response the wheel power of the vehicle in order to optimize vehicle shifting, while reducing the potential for shift cycling.

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Morton, IL, United States of America

Douglas A Carlson